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Wednesday, August 14, 2013

Gettin' Jiggy

The frame building jig is still coming together. Lori at RT Machining in Ballard is working on the pieces that need to be machined to center the bottom bracket, head tube, and seat tube.

The main triangle in the jig. A rear axle spacer will be added to the rear of the main jig backbone, aligning the rear dropouts at the appropriate distance for brazing.

Centering the head tube in the jig with two conical pieces machined to be threaded onto a piece of M8 threaded rod.

The seat post center had to be machined to fit inside the seat tube cluster, rather than using a wedge, as the top of the seat lug isn't cut square to the seat tube.

The bottom bracket center block, ready to be machined down to the thickness required to hold it off the jig by the necessary amount to center it. Threaded rod will be inserted into its center, then the last of the conical wedges will be threaded on the outside to center it.